WEBVTT 00:00:00.119 --> 00:00:02.150 Reading an engineering drawing is hard. 00:00:02.359 --> 00:00:06.210 It's a foreign language and it takes practice and it takes skill 00:00:06.599 --> 00:00:08.720 to know how to read those engineering drawings. 00:00:09.500 --> 00:00:10.880 In this particular course, 00:00:11.010 --> 00:00:15.600 I know you've been given some complex drawing sets that you need to try to digest. 00:00:15.930 --> 00:00:18.760 It can be frustrating and it is definitely difficult. 00:00:19.049 --> 00:00:20.440 In this particular video, 00:00:20.690 --> 00:00:23.559 I'm gonna take you straight into my iPad and together 00:00:23.770 --> 00:00:27.940 we're gonna look around at the engineering drawing for the NES 00:00:28.569 --> 00:00:32.770 front cover for the Nintendo game controller for the NES system. 00:00:33.110 --> 00:00:35.750 And what I'm going to do is talk through 00:00:36.159 --> 00:00:38.790 how to extract essential information 00:00:39.159 --> 00:00:39.590 from 00:00:39.799 --> 00:00:41.450 the engineering drawing set. 00:00:41.770 --> 00:00:42.110 All right, 00:00:42.279 --> 00:00:44.340 so just pulling a chair up over here, 00:00:44.599 --> 00:00:46.630 looking at the engineering drawing now. 00:00:48.090 --> 00:00:50.979 Any time you have an engineering drawing, 00:00:51.169 --> 00:00:55.409 you've got to spend time actually reading the engineering drawing 00:00:55.750 --> 00:00:58.639 and so what I've what I'm doing right now, 00:00:58.939 --> 00:01:00.450 I'm taking a look at a couple of things, 00:01:00.569 --> 00:01:02.889 maybe I'll highlight where I'm sort of looking. 00:01:03.369 --> 00:01:05.449 First thing I'm doing is I've come down here to 00:01:05.449 --> 00:01:09.620 see how many pages or sheets are in this drawing set 00:01:09.930 --> 00:01:11.650 that's alerting me to 00:01:12.330 --> 00:01:16.199 the extent of the information that I need to be looking for 00:01:16.410 --> 00:01:17.319 and through. 00:01:18.639 --> 00:01:22.709 I'm also taking a look at what's going on up here with the revision block. 00:01:23.239 --> 00:01:27.029 I'm seeing that there was a corrected dimension on a rim groove. 00:01:27.400 --> 00:01:31.550 I like to just know what rev I'm looking at and why I'm looking at it. 00:01:32.120 --> 00:01:32.529 I 00:01:32.680 --> 00:01:36.599 like to start by just sort of glancing through each of the sheets 00:01:37.000 --> 00:01:40.709 and understanding what I might be seeing on each of the pages. 00:01:41.199 --> 00:01:41.750 In this case, 00:01:41.839 --> 00:01:42.279 I 00:01:42.319 --> 00:01:45.440 am seeing the front face and I'm seeing the front face again 00:01:45.970 --> 00:01:49.319 with a bunch of dimensions here for the whole cutouts, 00:01:49.650 --> 00:01:51.919 and then there seems to be this little rim 00:01:52.569 --> 00:01:55.319 that goes around this stuff right here, 00:01:55.610 --> 00:01:57.959 these seem to be defined in this view. 00:01:58.839 --> 00:01:59.739 Right here, 00:02:00.480 --> 00:02:02.720 seeing another cross-section and another note. 00:02:03.930 --> 00:02:04.209 OK, 00:02:04.309 --> 00:02:06.949 on this one, I'm seeing all of the underside 00:02:07.510 --> 00:02:08.139 objects 00:02:08.470 --> 00:02:12.300 as well as having an ISO view here which is helpful, 00:02:12.550 --> 00:02:14.669 so don't have to go all the way back to sheet 1. 00:02:14.990 --> 00:02:17.589 I can see that this page is going to be 00:02:17.949 --> 00:02:21.250 helping me understand how to create these thin-walled 00:02:21.690 --> 00:02:24.229 features that are sort of in these areas. 00:02:25.520 --> 00:02:25.779 OK, 00:02:25.899 --> 00:02:28.690 and then I see there's at least 3 cross-sections here, 00:02:29.020 --> 00:02:31.490 just trying to get a sense for what's in the drawing. 00:02:31.860 --> 00:02:34.529 And then here all these screw bosses, 00:02:34.779 --> 00:02:37.070 this is a screw boss right here by the way, 00:02:37.440 --> 00:02:40.669 all these screw bosses are defined, their location, 00:02:41.139 --> 00:02:42.089 their heights, 00:02:42.460 --> 00:02:42.899 etc. 00:02:45.009 --> 00:02:47.970 And then in the last page of the drawing, 00:02:48.460 --> 00:02:50.009 we have this whole, 00:02:50.300 --> 00:02:52.990 this whole situation that's going on in detail 00:02:53.020 --> 00:02:53.429 'J' 00:02:54.020 --> 00:02:55.529 is being defined out 00:02:55.860 --> 00:02:56.889 on this sheet. 00:02:57.179 --> 00:02:59.619 That's where the cable comes out of the controller. 00:03:00.089 --> 00:03:02.399 And so, I've spent about a minute 00:03:02.699 --> 00:03:04.699 just glancing through these five sheets. 00:03:04.779 --> 00:03:06.339 I have a sense for what's in here. 00:03:06.419 --> 00:03:07.770 I haven't absorbed any 00:03:08.139 --> 00:03:09.300 deep information yet, 00:03:09.380 --> 00:03:10.169 but I have 00:03:10.500 --> 00:03:13.570 checked to just sort of see what is there, 00:03:13.779 --> 00:03:14.130 OK? 00:03:14.259 --> 00:03:18.449 I've also spent a little bit of time glancing at the title block, 00:03:18.899 --> 00:03:20.729 particularly in this area, 00:03:21.539 --> 00:03:23.419 to understand a couple of things. 00:03:23.970 --> 00:03:26.929 This model needs to be created in millimeter units. 00:03:27.250 --> 00:03:29.320 The model material 00:03:29.970 --> 00:03:31.339 needs to be ABS, 00:03:31.649 --> 00:03:33.679 and then there is a texture on it, 00:03:33.770 --> 00:03:35.880 MT11010, 00:03:36.410 --> 00:03:39.000 and there is a color specification that's given. 00:03:39.410 --> 00:03:41.850 So, there's a lot of stuff that's been given right there that's 00:03:41.850 --> 00:03:44.279 going to be essential for me as I create this model, 00:03:44.850 --> 00:03:47.360 especially as I begin the modeling process, 00:03:47.449 --> 00:03:50.529 I've got to absolutely make sure that my units are right, 00:03:51.320 --> 00:03:54.839 that can cause a bit of trouble if I'm starting in inches. 00:03:55.550 --> 00:03:58.240 And then I need to switch this to millimeters. 00:03:59.119 --> 00:04:01.880 The other thing I'm noticing here that's quite helpful for me 00:04:02.279 --> 00:04:06.690 is this data right here that shows what the mass 00:04:06.960 --> 00:04:09.110 of this finished top cover is. 00:04:09.399 --> 00:04:11.460 That's going to be helpful for me as I 00:04:11.839 --> 00:04:14.270 analyze my model and go along, 00:04:15.039 --> 00:04:15.350 during 00:04:15.350 --> 00:04:16.238 the modeling process, 00:04:16.279 --> 00:04:18.070 that's going to be helpful 00:04:18.279 --> 00:04:18.678 to me. 00:04:19.358 --> 00:04:19.760 OK, 00:04:19.880 --> 00:04:23.690 so that's the first part of just sort of absorbing 00:04:24.000 --> 00:04:26.630 an engineering drawing set is just to 00:04:26.959 --> 00:04:28.679 give it a once over, 00:04:29.750 --> 00:04:33.399 then we need to start thinking about how to extract out 00:04:33.829 --> 00:04:37.070 the essential information that's in this drawing. 00:04:37.269 --> 00:04:37.450 Now, 00:04:37.510 --> 00:04:38.600 a couple of tips. 00:04:38.910 --> 00:04:39.959 Item number 1 00:04:40.799 --> 00:04:43.350 is that engineering drawings are often 00:04:44.040 --> 00:04:47.029 created in a sort of hierarchical way, 00:04:47.440 --> 00:04:51.309 meaning that the top level information is on page 1 00:04:51.600 --> 00:04:54.380 and the more detailed information is later 00:04:54.640 --> 00:04:55.559 in the process. 00:04:56.049 --> 00:04:58.350 So, if you're getting started with your model, 00:04:58.630 --> 00:05:03.279 the first CAD modeling steps are likely going to be coming from 00:05:03.279 --> 00:05:06.549 the details found in the first couple of pages of the drawing 00:05:06.799 --> 00:05:08.079 versus the latter 00:05:08.440 --> 00:05:09.170 pages 00:05:09.399 --> 00:05:10.920 or sheets in the drawing. 00:05:11.019 --> 00:05:12.149 So, for example, 00:05:12.440 --> 00:05:17.470 if I was going to start the process of making this model, 00:05:17.799 --> 00:05:20.190 I've got to ask myself some key things like 00:05:20.519 --> 00:05:22.920 what is the overall width and what is the overall height, 00:05:23.000 --> 00:05:24.399 and what is the overall thickness 00:05:25.070 --> 00:05:27.540 of this basic prism 00:05:27.869 --> 00:05:29.899 that this thing is made of? 00:05:31.239 --> 00:05:34.850 Take a look at the drawing now and see if you can extract that out 00:05:35.480 --> 00:05:36.630 in a reasonable 00:05:36.920 --> 00:05:37.390 way. 00:05:38.829 --> 00:05:41.739 What you should be looking for here is 00:05:42.070 --> 00:05:43.380 the largest dimension, 00:05:43.470 --> 00:05:44.700 here is my length. 00:05:45.510 --> 00:05:50.750 My next dimension here is my total sort of height as it would appear in this 00:05:51.630 --> 00:05:51.869 or 00:05:51.989 --> 00:05:52.589 the width, 00:05:52.670 --> 00:05:53.769 I guess we could say 00:05:54.109 --> 00:05:55.100 in this view, 00:05:55.429 --> 00:05:58.140 and then I have the height or the thickness 00:05:58.880 --> 00:05:59.880 of this 00:06:00.239 --> 00:06:02.510 overall part shown right here. 00:06:02.839 --> 00:06:07.950 These three dimensions are essential for me as I get started in my CAD model 00:06:08.320 --> 00:06:10.410 because I'm gonna start by creating 00:06:10.839 --> 00:06:15.700 some chunk of material out of which I will cut out a bunch of holes and other stuff 00:06:16.040 --> 00:06:16.750 like this 00:06:17.239 --> 00:06:19.029 and these three dimensions, 00:06:19.290 --> 00:06:20.119 the width. 00:06:21.000 --> 00:06:21.470 Excuse me, 00:06:21.480 --> 00:06:22.029 the length, 00:06:22.179 --> 00:06:22.829 the width, 00:06:22.920 --> 00:06:23.890 and the height 00:06:24.239 --> 00:06:25.750 are super helpful. 00:06:26.040 --> 00:06:30.920 But I can also notice a really important thing that's going on here and that is that 00:06:31.279 --> 00:06:32.320 we 00:06:32.720 --> 00:06:33.950 have 00:06:36.070 --> 00:06:36.970 basically 00:06:36.970 --> 00:06:37.579 like 00:06:37.779 --> 00:06:38.940 a trapezoidal 00:06:39.470 --> 00:06:40.100 prism 00:06:40.350 --> 00:06:41.220 in this shape. 00:06:41.429 --> 00:06:41.790 In other words, 00:06:41.820 --> 00:06:42.980 they do not have 00:06:43.230 --> 00:06:44.350 vertical walls. 00:06:45.459 --> 00:06:49.779 And this means I'm going to have to start my CAD work in a particular way, 00:06:50.190 --> 00:06:53.190 because the first piece that I wanna pop in here 00:06:54.470 --> 00:06:56.299 that isn't actually going to be 00:06:56.549 --> 00:06:57.670 a rectangular prism, 00:06:57.720 --> 00:07:00.619 it's going to be more like a trapezoidal prism, 00:07:00.910 --> 00:07:02.839 and I have to start to understand 00:07:03.429 --> 00:07:04.329 that shape. 00:07:04.630 --> 00:07:06.779 This is what it looks like from the right side, 00:07:07.170 --> 00:07:09.799 also from the front view right here, 00:07:10.109 --> 00:07:11.619 we're seeing the same thing, 00:07:11.790 --> 00:07:12.010 OK, 00:07:12.109 --> 00:07:13.059 we're seeing a 00:07:13.350 --> 00:07:14.480 trapezoidal 00:07:14.829 --> 00:07:16.589 inward sort of 00:07:17.929 --> 00:07:20.040 slanting to those walls. 00:07:20.209 --> 00:07:21.079 So, this is a really, 00:07:21.320 --> 00:07:24.239 really important bit of information to extract from 00:07:24.570 --> 00:07:25.369 this drawing set. 00:07:25.529 --> 00:07:25.720 Now, 00:07:25.769 --> 00:07:28.609 the major question is how much does it slant in? 00:07:29.480 --> 00:07:29.989 Well, 00:07:30.200 --> 00:07:32.829 we luckily have this detail view right here 00:07:33.119 --> 00:07:37.750 that is telling us that something important is going on in this section, 00:07:38.079 --> 00:07:40.630 and we can go find that in Detail A. 00:07:41.040 --> 00:07:42.040 Let's go find Detail A. 00:07:42.119 --> 00:07:43.190 Here's Detail A. 00:07:44.570 --> 00:07:44.950 And 00:07:45.149 --> 00:07:46.799 Detail A has 00:07:47.290 --> 00:07:48.820 some important information and frankly, 00:07:48.929 --> 00:07:50.760 we need to step back just a second 00:07:51.130 --> 00:07:51.839 and say, 00:07:52.869 --> 00:07:56.700 "One of the first things we have to do whenever we start the drawing, 00:07:56.709 --> 00:07:57.230 reading, 00:07:57.309 --> 00:07:58.019 the drawing, 00:07:58.149 --> 00:07:58.559 the 00:07:58.589 --> 00:08:02.540 reading of the drawing is we need to really pay attention to the notes. 00:08:02.910 --> 00:08:04.420 The notes are there to help, 00:08:04.709 --> 00:08:04.899 like, 00:08:04.910 --> 00:08:07.500 to guide and to give direction and to help, 00:08:07.829 --> 00:08:09.160 you know what 00:08:09.549 --> 00:08:11.970 the creator of the drawing wanted you to know. 00:08:12.470 --> 00:08:13.600 So, we can see, 00:08:13.630 --> 00:08:14.149 for example, 00:08:14.309 --> 00:08:16.299 hidden lines are removed for clarity. 00:08:16.880 --> 00:08:17.609 OK, 00:08:17.809 --> 00:08:20.920 there's a virtual sharp in Detail A that's 00:08:20.920 --> 00:08:23.640 interesting because we're looking at Detail A right now, 00:08:24.049 --> 00:08:27.119 and there's something about detail A that's being told to us. 00:08:27.730 --> 00:08:30.549 General wall thicknesses are shown in section AA. 00:08:30.570 --> 00:08:30.649 Well, 00:08:30.809 --> 00:08:32.400 here's section AA, 00:08:32.820 --> 00:08:33.489 OK? 00:08:33.929 --> 00:08:37.770 And section AA is shown as a slice and not a full cross-section. 00:08:38.258 --> 00:08:39.698 If it was a full cross-section, 00:08:39.739 --> 00:08:40.979 what this would mean 00:08:41.258 --> 00:08:43.129 is that we would actually see 00:08:43.457 --> 00:08:45.658 the rest of the object here 00:08:45.898 --> 00:08:46.939 without a crosshatch, 00:08:47.018 --> 00:08:48.338 but we'd be able to see, 00:08:48.698 --> 00:08:48.818 you know, 00:08:48.939 --> 00:08:51.328 there'd be like posts and some other stuff, 00:08:51.698 --> 00:08:52.098 and it 00:08:52.138 --> 00:08:53.568 would get quite cluttered. 00:08:53.658 --> 00:08:54.568 So, in this case, 00:08:54.939 --> 00:08:55.989 for clarity's sake, 00:08:56.138 --> 00:08:59.208 section AA was provided as only a slice. 00:09:00.539 --> 00:09:01.219 OK, 00:09:01.469 --> 00:09:03.219 now what is a virtual sharp? 00:09:03.299 --> 00:09:03.549 OK, 00:09:03.590 --> 00:09:07.419 we need to go understand what a virtual sharp is. Because a virtual sharp 00:09:07.719 --> 00:09:10.179 is appearing in detail A 00:09:10.510 --> 00:09:12.299 and this is an important 00:09:12.669 --> 00:09:15.979 part of knowing how the trapezoidal prism 00:09:16.270 --> 00:09:17.979 geometry should be made. 00:09:18.469 --> 00:09:20.429 So, this little thing that we have here, 00:09:20.469 --> 00:09:22.700 I'm going to point to it right now before I draw on it, 00:09:22.950 --> 00:09:24.580 that little plus that's there 00:09:24.869 --> 00:09:26.469 is the virtual sharp. 00:09:26.940 --> 00:09:28.330 What this means is 00:09:28.700 --> 00:09:30.890 that if this object 00:09:31.500 --> 00:09:33.109 did not have a fillet 00:09:33.789 --> 00:09:35.080 in its corner, 00:09:35.250 --> 00:09:35.650 right up there, 00:09:35.729 --> 00:09:37.359 there's a fillet right in there. 00:09:37.770 --> 00:09:39.200 It would have a sharp point, 00:09:39.530 --> 00:09:41.280 like what we're seeing right over here. 00:09:41.570 --> 00:09:43.359 And that sharp point 00:09:43.690 --> 00:09:46.010 would be something that could be dimension too. 00:09:47.530 --> 00:09:50.690 And when that sharp point goes away, 00:09:51.020 --> 00:09:54.820 such as when there's a filet that's added to something like this, 00:09:57.020 --> 00:09:57.549 then 00:09:57.760 --> 00:09:57.810 a 00:09:57.760 --> 00:09:59.750 marker can go right here. 00:10:00.000 --> 00:10:02.070 Let's see if I can switch this color 00:10:02.520 --> 00:10:03.340 and 00:10:03.640 --> 00:10:05.190 make this even more obvious, 00:10:05.640 --> 00:10:06.190 OK? 00:10:06.520 --> 00:10:11.179 Then a marker can go right there exactly where the sharp point would have been, 00:10:11.479 --> 00:10:11.820 therefore 00:10:11.840 --> 00:10:13.609 it is called a virtual sharp. 00:10:13.919 --> 00:10:16.150 That can be valuable because 00:10:16.440 --> 00:10:18.289 if we want to dimension 00:10:18.960 --> 00:10:19.719 to that 00:10:20.210 --> 00:10:22.179 we can and we do the dimension to 00:10:22.179 --> 00:10:24.890 the virtual sharp and that's actually what's going on 00:10:25.250 --> 00:10:25.729 right here. 00:10:25.849 --> 00:10:28.000 This 0.85 typical 00:10:28.369 --> 00:10:30.590 is going to this virtual sharp. 00:10:30.849 --> 00:10:32.280 That helps us to know 00:10:32.650 --> 00:10:33.770 what size 00:10:36.349 --> 00:10:37.820 that trapezoidal prism 00:10:38.070 --> 00:10:39.099 is made at. 00:10:39.729 --> 00:10:39.869 All right, 00:10:40.039 --> 00:10:44.549 so I'm seeing those 3 or 4 critical dimensions that help 00:10:44.549 --> 00:10:48.419 me get my first chunk of material into the CAD system. 00:10:49.070 --> 00:10:52.580 Once I have that basic chunk of material into the CAD system, 00:10:52.909 --> 00:10:55.739 it's a matter of me starting to chip away 00:10:56.030 --> 00:10:57.200 at producing 00:10:57.549 --> 00:10:59.940 the geometries associated with that. 00:11:00.500 --> 00:11:00.940 So, 00:11:01.140 --> 00:11:01.809 I 00:11:01.820 --> 00:11:03.099 can see that 00:11:03.619 --> 00:11:04.890 because there is 00:11:05.340 --> 00:11:07.609 some attempt to describe, 00:11:07.780 --> 00:11:09.530 I'll switch colors here for a second, 00:11:09.780 --> 00:11:13.729 there's some attempt to describe a general wall thickness, 00:11:14.140 --> 00:11:17.049 it's most likely that a shell is used 00:11:17.380 --> 00:11:18.780 somewhere in this set, 00:11:18.820 --> 00:11:21.469 because the shell gives us a nice constant 00:11:21.909 --> 00:11:26.390 wall thickness, and I can see that the wall thickness is shown in section AA, 00:11:26.780 --> 00:11:27.539 (whereas it's shown), 00:11:27.580 --> 00:11:28.650 it's right here. 00:11:29.520 --> 00:11:30.119 OK. 00:11:31.159 --> 00:11:33.429 If we're going to look at something that's called general. 00:11:34.909 --> 00:11:36.940 Then we're gonna look for something that's called typical 00:11:38.000 --> 00:11:39.840 because typical 'TYP' 00:11:40.200 --> 00:11:41.140 means that 00:11:41.510 --> 00:11:42.940 this same thickness 00:11:43.510 --> 00:11:44.349 that's here 00:11:44.669 --> 00:11:49.669 also exists here, and also exists here, and also exists here, and also exists here, and 00:11:49.989 --> 00:11:51.280 here, and here 00:11:51.869 --> 00:11:52.400 and 00:11:52.549 --> 00:11:53.309 throughout. 00:11:54.229 --> 00:11:55.700 It's a little different over here, 00:11:55.780 --> 00:11:56.200 but 00:11:56.460 --> 00:11:57.369 nevertheless, 00:11:57.739 --> 00:11:58.619 everywhere 00:11:59.450 --> 00:12:02.039 in those areas, we would have constant wall thickness. 00:12:02.109 --> 00:12:02.469 So, 00:12:02.950 --> 00:12:03.669 what have I done? 00:12:03.750 --> 00:12:05.270 I have gone into my drawing. 00:12:05.309 --> 00:12:09.299 I've tried to figure out how am I going to create my first basic shape. 00:12:09.789 --> 00:12:12.940 I've looked at the drawing to pick out 00:12:13.299 --> 00:12:16.869 the, the dimensions that are most likely the 00:12:16.869 --> 00:12:19.659 ones that I need to create that basic geometry. 00:12:20.270 --> 00:12:20.619 Now 00:12:20.960 --> 00:12:22.119 it's worth knowing 00:12:22.590 --> 00:12:26.299 that there's a lot of information here that's not needed yet. 00:12:27.280 --> 00:12:27.520 OK, 00:12:27.599 --> 00:12:30.950 so I'm trying to build out my basic trapezoidal prism. 00:12:31.299 --> 00:12:33.520 There's some stuff I just don't have to worry about, 00:12:33.559 --> 00:12:33.799 OK? 00:12:33.840 --> 00:12:35.429 I don't have to worry about, 00:12:35.719 --> 00:12:36.000 you know, 00:12:36.119 --> 00:12:36.880 this dimension, 00:12:36.940 --> 00:12:37.440 for example, 00:12:37.479 --> 00:12:38.630 or this dimension. 00:12:38.919 --> 00:12:40.590 Those are going to come later. 00:12:40.880 --> 00:12:42.799 And the reason why this is important is because 00:12:42.799 --> 00:12:45.750 there's a lot of information on these drawing sets 00:12:46.140 --> 00:12:46.750 and 00:12:47.200 --> 00:12:49.479 you have to be able to start to pick out what 00:12:49.479 --> 00:12:53.010 is the important information and what is the not important information 00:12:53.320 --> 00:12:55.239 for the given step that you're working on. 00:12:55.630 --> 00:12:59.539 And if you had a CAD strategy and your CAD strategy looked something like this, 00:12:59.880 --> 00:13:01.190 like you're going to 00:13:01.830 --> 00:13:04.950 draw one plane and then I'm gonna switch colors here for a second. 00:13:05.119 --> 00:13:07.030 You're gonna draw another plane like this, 00:13:07.200 --> 00:13:07.700 OK? 00:13:08.070 --> 00:13:11.020 And then you are going to extrude between them 00:13:11.280 --> 00:13:14.270 and create some sort of trapezoidal prism. 00:13:14.559 --> 00:13:17.510 You would need to know how to first draw 00:13:18.200 --> 00:13:21.559 one of those sketches and then how to draw the other sketch, 00:13:21.900 --> 00:13:23.630 and what those dimensions would be. 00:13:23.710 --> 00:13:23.950 So, you're 00:13:25.010 --> 00:13:27.789 looking for those in the drawing set. 00:13:28.719 --> 00:13:29.349 All right, 00:13:29.479 --> 00:13:30.229 now, 00:13:30.559 --> 00:13:31.330 what 00:13:31.729 --> 00:13:32.719 else 00:13:32.799 --> 00:13:33.840 should we say about this, 00:13:33.880 --> 00:13:34.510 OK? 00:13:37.260 --> 00:13:38.609 It's important to know, 00:13:38.940 --> 00:13:40.390 while you are 00:13:40.780 --> 00:13:44.489 looking around drawings for particular bits of information, 00:13:44.820 --> 00:13:47.530 there's a couple of rules that you should know about. 00:13:47.979 --> 00:13:48.780 Number one, 00:13:50.409 --> 00:13:50.609 well, 00:13:50.770 --> 00:13:53.000 we don't have any hidden lines on this drawing, 00:13:53.010 --> 00:13:55.250 and that's actually good for you right now, 00:13:55.669 --> 00:13:55.909 but 00:13:56.010 --> 00:13:58.039 you should know that 00:13:58.130 --> 00:14:01.369 you're not allowed to dimension to hidden lines on drawings. 00:14:01.450 --> 00:14:03.640 This is part of the ASME standards. 00:14:03.890 --> 00:14:06.440 You're not allowed to dimension to a hidden line, 00:14:06.729 --> 00:14:08.450 and that would mean that if I wanted to know, 00:14:08.510 --> 00:14:09.400 for example, 00:14:09.729 --> 00:14:11.640 how tall is this post? 00:14:12.049 --> 00:14:14.010 Can we go look at the isometric view for a 00:14:14.010 --> 00:14:15.570 second so we can know what we're talking about. 00:14:15.700 --> 00:14:17.609 I want to know how high is that post. 00:14:18.289 --> 00:14:21.450 There's only one way for me to know this in this drawing set 00:14:21.450 --> 00:14:23.840 and that is that I have to look for a cross-section, 00:14:24.130 --> 00:14:24.530 OK? 00:14:24.609 --> 00:14:27.520 And so, let's go see if we can find that cross-section. 00:14:27.809 --> 00:14:27.909 Well, 00:14:27.929 --> 00:14:29.840 there's a cross-section B right here. 00:14:30.760 --> 00:14:31.239 OK, 00:14:31.479 --> 00:14:34.039 this is cross-section B and there's no post in that one, 00:14:34.080 --> 00:14:35.280 so that's not gonna be it. 00:14:35.950 --> 00:14:36.190 OK, 00:14:36.270 --> 00:14:38.270 here's some other cross-sections here, 00:14:38.650 --> 00:14:38.750 but 00:14:38.869 --> 00:14:41.270 none of them go through the post I was wanting, 00:14:41.309 --> 00:14:42.260 which was that one. 00:14:42.929 --> 00:14:43.419 OK. 00:14:43.909 --> 00:14:45.450 So that's a little bit 00:14:45.450 --> 00:14:46.059 difficult. 00:14:52.349 --> 00:14:52.450 See 00:14:52.450 --> 00:14:54.059 what else we have going on here. 00:14:55.049 --> 00:14:55.599 OK? 00:14:56.849 --> 00:14:57.020 "Oh, 00:14:57.030 --> 00:14:57.230 here 00:14:57.230 --> 00:14:57.710 we go. 00:14:58.090 --> 00:14:59.320 Section-F 00:15:00.049 --> 00:15:02.929 goes right through the exact post that I want, 00:15:03.330 --> 00:15:04.919 and here's section-F. 00:15:05.820 --> 00:15:06.450 Right here, 00:15:06.580 --> 00:15:08.250 and it is telling me 00:15:08.539 --> 00:15:09.770 the height of that post, 00:15:09.979 --> 00:15:12.979 the height of that post is 5.68. 00:15:14.150 --> 00:15:14.309 All right, 00:15:14.380 --> 00:15:16.150 the height of that post is 5.68. 00:15:16.390 --> 00:15:17.750 Another thing you should know about drawings 00:15:17.750 --> 00:15:20.780 is you're extracting information from drawings, 00:15:21.070 --> 00:15:22.299 and that is 00:15:22.669 --> 00:15:23.299 that 00:15:23.710 --> 00:15:24.820 lines that, 00:15:25.070 --> 00:15:25.510 for example, 00:15:25.559 --> 00:15:26.469 I'm gonna look right in here, 00:15:26.570 --> 00:15:27.010 OK? 00:15:27.349 --> 00:15:30.039 Lines that appear to be right angles 00:15:30.469 --> 00:15:33.030 are assumed to be right angles, 00:15:33.150 --> 00:15:34.549 that's supposed to be 90, 00:15:34.669 --> 00:15:34.989 OK. 00:15:36.429 --> 00:15:36.650 Lines 00:15:36.650 --> 00:15:39.590 that appear to be on the same line 00:15:39.789 --> 00:15:40.869 such as this 00:15:42.169 --> 00:15:44.640 are actually on the same line. 00:15:45.359 --> 00:15:47.679 And these are important things to know about drawing. 00:15:47.750 --> 00:15:48.729 So, for 00:15:48.729 --> 00:15:49.059 example, 00:15:50.190 --> 00:15:50.619 because, 00:15:50.789 --> 00:15:53.340 let's see if I can undo that one that I just did, 00:15:53.599 --> 00:15:53.979 OK. 00:15:54.309 --> 00:15:54.619 The 00:15:54.830 --> 00:15:56.940 height of this post 00:15:57.309 --> 00:15:58.460 is this much 00:15:58.830 --> 00:16:02.500 and the height of that post is also that same amount, 00:16:02.869 --> 00:16:07.900 5.68, because they appear to be on the same line, 00:16:08.530 --> 00:16:08.739 OK? 00:16:08.979 --> 00:16:11.140 Same thing goes with lines that are flat 00:16:11.390 --> 00:16:12.070 appear to be flat 00:16:12.150 --> 00:16:13.309 are actually flat, 00:16:13.669 --> 00:16:16.169 and all that kind of wonderful stuff. 00:16:16.539 --> 00:16:16.739 OK, 00:16:16.840 --> 00:16:18.940 what else do we need to know about this? 00:16:19.219 --> 00:16:20.489 We need to know that 00:16:20.780 --> 00:16:23.090 there are some symbols on here that 00:16:23.239 --> 00:16:24.570 need to be described. 00:16:24.859 --> 00:16:25.020 OK. 00:16:25.130 --> 00:16:26.659 This is a complex one, 00:16:26.700 --> 00:16:27.299 for example, 00:16:27.390 --> 00:16:28.020 OK? 00:16:28.179 --> 00:16:29.950 This means that there are 6 00:16:31.250 --> 00:16:36.549 features that have a diameter of 1.44, 00:16:36.960 --> 00:16:38.760 see if we can think about what that is, 00:16:39.049 --> 00:16:39.650 there's 1, 00:16:39.849 --> 00:16:40.640 there's 2, 00:16:40.729 --> 00:16:41.479 there's 3, 00:16:41.530 --> 00:16:42.210 there's 4, 00:16:42.349 --> 00:16:42.960 there's 5, 00:16:42.969 --> 00:16:44.039 and there's 6. 00:16:44.330 --> 00:16:46.109 How do I know that those are the ones? 00:16:46.530 --> 00:16:48.320 Because when you come over here and you look at this, 00:16:49.010 --> 00:16:51.080 all 6 of those look similar. 00:16:51.729 --> 00:16:51.900 OK, 00:16:51.929 --> 00:16:55.210 I got to get back to sketching and not erasing 00:16:55.489 --> 00:16:55.890 that one, 00:16:55.969 --> 00:16:56.440 that one, 00:16:56.570 --> 00:16:57.090 that one, 00:16:57.250 --> 00:16:57.830 that one, 00:16:57.849 --> 00:16:59.690 and that one and that one. 00:17:00.239 --> 00:17:02.830 All appear similar. And in this 00:17:03.520 --> 00:17:06.670 drawing image they also all appear similar 00:17:07.040 --> 00:17:10.209 and the fact that there's a dimension that says 6X 00:17:10.560 --> 00:17:11.329 means 00:17:11.800 --> 00:17:12.630 that they are. 00:17:12.959 --> 00:17:15.108 Now what does this symbol here mean? 00:17:15.560 --> 00:17:18.329 This means that there is a hole, 00:17:18.880 --> 00:17:20.300 and it's pointing to a hole, 00:17:20.520 --> 00:17:20.739 OK, 00:17:20.800 --> 00:17:22.750 you can see it pointing right there to that hole. 00:17:23.000 --> 00:17:24.510 This hole that's right here 00:17:25.239 --> 00:17:25.989 is 00:17:26.329 --> 00:17:29.089 5.68 millimeters deep. 00:17:30.119 --> 00:17:30.390 Now, 00:17:30.439 --> 00:17:34.069 if we couple that together with what we saw in the cross-section, 00:17:34.760 --> 00:17:36.229 we can actually see that hole, 00:17:36.359 --> 00:17:37.229 it's right there. 00:17:38.060 --> 00:17:38.260 OK, 00:17:38.270 --> 00:17:40.569 it goes all the way down right there and it 00:17:40.859 --> 00:17:42.849 is in line with this. 00:17:43.180 --> 00:17:46.020 And so, we know actually that we've interpreted that 00:17:46.500 --> 00:17:47.209 correctly. 00:17:47.459 --> 00:17:49.369 Let's see if there's anything else in here that's 00:17:49.540 --> 00:17:52.089 interesting to talk about right now 00:17:52.500 --> 00:17:53.410 other than 00:17:53.900 --> 00:17:56.030 the stuff we have already talked about. 00:17:56.300 --> 00:17:57.890 I think this is a good one right here. 00:17:57.939 --> 00:17:59.500 Let's take a look at this for a minute. 00:18:01.069 --> 00:18:03.420 Maybe this drawing has more than one that will help us, 00:18:03.469 --> 00:18:03.670 OK, 00:18:03.790 --> 00:18:04.390 this is good. 00:18:05.150 --> 00:18:07.310 There are two things going on on this drawing that 00:18:07.310 --> 00:18:09.709 are on this view that are worth thinking about. 00:18:10.069 --> 00:18:11.900 One is the fact that sometimes 00:18:12.109 --> 00:18:13.459 8X is used 00:18:13.910 --> 00:18:16.280 and sometimes a thing called typical is used. 00:18:16.349 --> 00:18:17.819 'TYP' means typical. 00:18:18.229 --> 00:18:18.349 Well, 00:18:18.430 --> 00:18:20.260 we already know the 8X version of this. 00:18:20.329 --> 00:18:22.469 It means that there's 8 radii 00:18:23.300 --> 00:18:24.800 of the same exact 00:18:25.099 --> 00:18:25.890 size, 00:18:26.300 --> 00:18:29.410 and they should be easily pick out a ball 00:18:29.819 --> 00:18:30.770 in this drawing. 00:18:30.979 --> 00:18:31.420 There's 1, 00:18:31.459 --> 00:18:31.819 there's 2, 00:18:31.939 --> 00:18:32.339 there's 3, 00:18:32.420 --> 00:18:32.780 there's 4, 00:18:32.859 --> 00:18:33.260 there's 5, 00:18:33.339 --> 00:18:33.699 there's 6, 00:18:33.780 --> 00:18:34.180 there's 7, 00:18:34.260 --> 00:18:34.969 there's 8. 00:18:35.260 --> 00:18:38.530 All 8 of those are 1.3. 00:18:39.020 --> 00:18:40.140 But over here, 00:18:41.130 --> 00:18:42.849 we have something different going on, 00:18:42.920 --> 00:18:43.430 OK? 00:18:43.709 --> 00:18:44.849 We don't have 00:18:45.219 --> 00:18:47.890 a certain number, 00:18:48.180 --> 00:18:48.380 you know, 00:18:48.500 --> 00:18:52.420 like 12X or something in front of this 1.00. 00:18:52.500 --> 00:18:55.410 We instead just have 1.00 typical. 00:18:55.800 --> 00:18:56.969 Why is that the case? 00:18:57.339 --> 00:18:57.540 Well, 00:18:57.699 --> 00:18:59.170 if we take a look at this guy, 00:18:59.500 --> 00:18:59.579 OK, 00:18:59.660 --> 00:19:02.530 and let's go erase some of this stuff that I had on here earlier. 00:19:03.219 --> 00:19:03.300 OK, 00:19:03.339 --> 00:19:04.260 if we look at this guy, 00:19:04.380 --> 00:19:05.939 I'm gonna turn this one to blue for a minute. 00:19:06.400 --> 00:19:13.270 I've got 1-2-3-4-5-6-7-8-9- 00:19:13.280 --> 00:19:14.359 10-11- 00:19:14.369 --> 00:19:15.430 12, 00:19:15.959 --> 00:19:17.619 but then I also have 00:19:18.300 --> 00:19:19.349 this one in red 00:19:19.640 --> 00:19:21.150 13-14- 00:19:21.160 --> 00:19:22.550 15-16- 00:19:22.560 --> 00:19:23.640 17-18- 00:19:23.650 --> 00:19:24.989 19-20. 00:19:25.400 --> 00:19:29.800 20 geometric features that have a dimension of 1, 00:19:30.359 --> 00:19:32.949 just in this particular part of the image. 00:19:33.420 --> 00:19:35.910 And so, the way that that's dealt with is not 00:19:36.199 --> 00:19:36.939 to say, 00:19:37.160 --> 00:19:37.239 well, 00:19:37.280 --> 00:19:38.079 what number did I say? 00:19:38.119 --> 00:19:38.400 I don't know, 00:19:38.439 --> 00:19:39.540 is it 16. 00:19:40.130 --> 00:19:40.160 No, 00:19:40.199 --> 00:19:41.150 it was 20. 00:19:41.869 --> 00:19:43.550 It's not to do this. 00:19:45.800 --> 00:19:46.709 But instead, 00:19:46.880 --> 00:19:50.050 it's to say 1.00 TYP. 00:19:50.939 --> 00:19:54.219 Because it's more obvious that that's what's going on 00:19:54.579 --> 00:19:55.699 in this area. 00:19:57.670 --> 00:19:58.319 OK, 00:19:58.589 --> 00:19:59.459 erasing those. 00:20:00.410 --> 00:20:00.430 All right, 00:20:01.119 --> 00:20:01.329 what 00:20:01.400 --> 00:20:03.000 else do we need to talk about? 00:20:03.160 --> 00:20:05.790 It's important to know that circles 00:20:06.199 --> 00:20:08.189 will always be designated 00:20:09.079 --> 00:20:12.910 by the standards as a diameter and arcs, 00:20:13.239 --> 00:20:14.339 not complete circles, 00:20:14.369 --> 00:20:16.680 will always be designated by a radius. 00:20:17.459 --> 00:20:20.469 It's also important to know that in engineering drawings, 00:20:20.479 --> 00:20:21.949 according to the standards, 00:20:22.319 --> 00:20:27.300 circles will only be dimensioned where they look like a circle. 00:20:27.630 --> 00:20:28.739 So, if I had a shaft, 00:20:28.750 --> 00:20:29.219 for example, 00:20:29.349 --> 00:20:30.540 that looked like this, 00:20:31.189 --> 00:20:33.819 and I had an engineering drawing that looked like this, 00:20:34.869 --> 00:20:37.540 I would dimension this one 00:20:37.910 --> 00:20:39.020 in this view, 00:20:40.209 --> 00:20:40.660 not 00:20:40.790 --> 00:20:41.589 like this. 00:20:42.849 --> 00:20:43.150 OK, 00:20:43.270 --> 00:20:45.459 this one is diameter something. 00:20:45.709 --> 00:20:46.979 This is no good. 00:20:47.270 --> 00:20:50.500 And the reason why I'm telling you that is because as you look for information, 00:20:50.750 --> 00:20:52.020 you want to make sure 00:20:52.270 --> 00:20:53.479 that you 00:20:53.869 --> 00:20:54.420 are 00:20:54.680 --> 00:20:55.939 looking in the right spot. 00:20:56.030 --> 00:20:58.069 So, if you're looking for the dimension of a circle, 00:20:58.150 --> 00:20:59.979 look where it actually appears 00:21:00.349 --> 00:21:00.810 like 00:21:01.069 --> 00:21:01.859 a circle. 00:21:02.270 --> 00:21:02.739 OK, 00:21:02.859 --> 00:21:05.430 a few things I want to just go over here for a second. 00:21:06.969 --> 00:21:10.569 As you're trying to extract out the information from these drawings, 00:21:10.790 --> 00:21:12.560 (let me just zoom out here for a second). 00:21:15.010 --> 00:21:16.280 We want to start 00:21:16.609 --> 00:21:21.640 by getting an overall view of the drawing by just scanning through it, 00:21:22.349 --> 00:21:24.020 understanding what images are there, 00:21:24.290 --> 00:21:26.280 trying to absorb a little bit of stuff, 00:21:26.449 --> 00:21:26.839 OK? 00:21:27.209 --> 00:21:28.979 We want to take a look at the title block, 00:21:29.130 --> 00:21:30.920 see what information is given there. 00:21:31.209 --> 00:21:33.000 We definitely want to read the notes, 00:21:33.489 --> 00:21:33.920 OK? 00:21:34.410 --> 00:21:37.920 And then we want to start getting the top level information 00:21:38.160 --> 00:21:39.270 that will help us 00:21:39.609 --> 00:21:42.719 to start building out the geometry. 00:21:43.089 --> 00:21:43.569 OK. 00:21:45.079 --> 00:21:45.279 While 00:21:45.279 --> 00:21:46.229 you're doing this, 00:21:46.359 --> 00:21:49.680 you want to learn to look for clues 00:21:50.239 --> 00:21:51.500 in the drawing, 00:21:51.520 --> 00:21:53.880 and I don't mean this from an educational perspective. 00:21:53.920 --> 00:21:56.109 I just mean that there are certain things like 00:21:56.599 --> 00:21:59.479 general wall thickness that's going to tell you 00:21:59.479 --> 00:22:01.270 there's going to be a shell somewhere, 00:22:01.560 --> 00:22:02.040 right? 00:22:02.280 --> 00:22:02.829 Or 00:22:03.170 --> 00:22:04.219 there are 00:22:04.520 --> 00:22:08.969 things like these virtual sharps that we saw here that mean that 00:22:09.319 --> 00:22:14.030 really we're trying to give a dimension before a radius would occur in a CAD model, 00:22:14.280 --> 00:22:14.400 right, 00:22:14.410 --> 00:22:16.829 or before a radius occurred in a manufacturing 00:22:17.310 --> 00:22:17.719 step. 00:22:18.609 --> 00:22:18.920 Also, 00:22:19.910 --> 00:22:19.985 we 00:22:19.985 --> 00:22:21.390 want to take a look at the cross-sections. 00:22:21.689 --> 00:22:24.439 We want to know that the cross-sections are there to help us 00:22:24.729 --> 00:22:26.959 and we want to really try to absorb the cross 00:22:26.959 --> 00:22:30.170 sections and understand what's going on with the cross-sections. 00:22:30.329 --> 00:22:32.800 Then we want to do our best to soak in the details 00:22:33.089 --> 00:22:34.619 of the detail view, 00:22:34.930 --> 00:22:35.170 right? 00:22:35.290 --> 00:22:36.760 What is this telling us? 00:22:36.810 --> 00:22:38.760 This is an interesting one right here, 00:22:38.969 --> 00:22:39.219 OK? 00:22:39.489 --> 00:22:39.859 Because 00:22:40.489 --> 00:22:41.439 this line 00:22:41.930 --> 00:22:43.140 and this line 00:22:43.619 --> 00:22:47.719 are parallel to each other and this line and this line are parallel to each other. 00:22:48.010 --> 00:22:49.479 This is interesting because 00:22:49.969 --> 00:22:51.979 there are other ways 00:22:52.369 --> 00:22:53.199 to 00:22:53.609 --> 00:22:55.280 have measured this. 00:22:55.479 --> 00:22:55.489 Yeah, 00:22:55.500 --> 00:22:56.800 we did this one and this one, 00:22:56.979 --> 00:22:57.329 OK? 00:22:58.239 --> 00:23:00.109 We could have measured like this, 00:23:00.280 --> 00:23:02.790 and these give us two different numbers actually, 00:23:03.040 --> 00:23:05.949 and this is something that can cause trouble in this particular 00:23:06.359 --> 00:23:06.930 model. 00:23:07.680 --> 00:23:08.439 So, 00:23:09.390 --> 00:23:09.510 understand 00:23:09.510 --> 00:23:10.229 what 00:23:10.520 --> 00:23:12.469 these things are telling you, 00:23:12.719 --> 00:23:13.239 OK? 00:23:13.680 --> 00:23:14.469 Also, 00:23:16.079 --> 00:23:16.175 most 00:23:16.175 --> 00:23:16.839 important, 00:23:16.920 --> 00:23:20.650 I think as you're looking through these engineering drawings is just to realize 00:23:21.020 --> 00:23:22.829 that the information is there. 00:23:23.199 --> 00:23:25.709 You don't need all of it at once. 00:23:26.060 --> 00:23:28.390 You need to use your CAD strategy 00:23:28.719 --> 00:23:31.839 to help you know just what bit you need, 00:23:32.199 --> 00:23:35.150 what feature you want to create so that you can get into this 00:23:35.510 --> 00:23:38.050 set of drawings and go find the essential 00:23:38.439 --> 00:23:39.430 dimensions 00:23:39.680 --> 00:23:41.359 that will help you get it. 00:23:41.959 --> 00:23:43.849 So, I'm coming back now to 00:23:44.130 --> 00:23:46.449 just sort of end of this and say that it 00:23:46.449 --> 00:23:49.849 is indeed really hard to read these engineering drawings. 00:23:50.010 --> 00:23:52.439 It is a foreign language in my view 00:23:52.650 --> 00:23:53.760 and it takes practice. 00:23:53.810 --> 00:23:54.650 It takes 00:23:55.010 --> 00:23:55.780 patience 00:23:56.130 --> 00:23:57.719 and it takes a willingness 00:23:58.130 --> 00:24:00.040 to actually read them, 00:24:00.329 --> 00:24:01.680 and to try to 00:24:02.130 --> 00:24:05.420 see what they're telling you, and to envision the geometry 00:24:05.689 --> 00:24:07.040 that's being described. 00:24:07.329 --> 00:24:08.410 And as you do that, 00:24:08.959 --> 00:24:10.579 your mind will be able to 00:24:10.880 --> 00:24:12.719 notice certain dimensions, 00:24:13.599 --> 00:24:14.689 certain features, 00:24:14.959 --> 00:24:15.800 certain patterns, 00:24:15.880 --> 00:24:16.790 certain other things 00:24:17.040 --> 00:24:17.869 that will help you 00:24:18.160 --> 00:24:20.270 during the CAD modeling process.